Toy powered flex wing



Dec. 14, 1965 w. 1.. EFFINGER, JR., ETAL 3,222,816

TOY POWERED FLEX WING Filed May 28, 1964 5 Sheets-Sheet 1 I K34 a7 a N tg INVENTORS MI/M 6M H T TORJVEYI Dec. 14, 1965 w. L. EFFINGER, JR.. ETAL 3,222,816

TOY POWERED FLEX WING Filed May 28, 1964 5 Sheets-Sheet 2 INVENTORS flTTORNEY.

w. EFFINGER, JR., ETAL 3,222,816

Dec. 14, 1965 TOY POWERED FLEX WING 5 Sheets-Sheet 5 Filed May 28, 1964 INVENTORS, 6. J5. 1401144 5 A TTORNE Y United States Patent 3,222,816 TOY POWERED FLEX WING William L. Eflinger, Jr., Hamden, and Henry Struck,

Hamburg, Conn., assignors to The A. C. Gilbert Company, New Haven, Conn., a corporation of Maryland Filed May 28, 1964, Ser. No. 370,815 17 Claims. (CI. 4678) This invention relates to a simplified economical version of a toy, self powered, gliding air craft of the flex Wing type utilizing principles of construction and aerodynamic action disclosed in a copending application, Serial No. 237,539 filed November 14, 1962, now Patent No. 3,153,877.

An object of the invention is to reduce to minimal essentials of structure, the craft disclosed in said copending application whereby to bring use of the toy within the understanding and maneuvering ability of relatively younger children.

A related object is to eliminate much of the time and attention that has been required to prepare a toy flex wing for flying particularly when self powered.

Another object is to reduce the consumer price for the toy into proximity to the cost of ordinary kites as distinguished from the relatively higher cost of model airplanes so that loss will correspondingly be lessened if the toy becomes damaged or destroyed in use.

Another object is automatically to counterbalance tendency of the simplified form of the craft to roll in a direction of rotation opposite to the direction in which the propeller rotates.

These and other objects of the invention will appear in fuller particular as the description proceeds with reference to the accompanying drawings wherein:

FIG. 1 is a perspective plan view of a simplified flex wing type of paraglider embodying the present improvements, one side of the stabilizer at the nose of the craft being broken away to expose in broken lines the manner of adjusting the driving power of the motivating elastic band.

FIG. 2 is a side elevation of the craft.

FIG. 3 is an enlarged view of a front portion of FIG. 2 showing the wall of the hollow main spar partially broken away to expose the adjustable anchorage of the motivating elastic band.

FIG. 4 is a view taken in section on the plane 4--4 in FIG. 3, looking in the direction of the arrows.

FIG. 5 is a sectional view taken on the plane 5-5 in FIG. 2 drawn on a scale intermediate FIG. 2 and FIG. 3, looking in the direction of the arrows.

FIG. 6 is a front view of the craft looking in the direction of arrow 6 in FIG. 2.

PEG. 7 is an enlarged view of a rear portion of FIG. 2 showing the wall of the hollow main spar partially broken away to expose the driving connection of the propeller to the motivating elastic band.

FIG. 8 is a view taken in section on the plane 8-8 in FIG. 3, looking in the direction of the arrows.

FIG. 8a is a fragmentary perspective view showing a simplified, lightweight and less costly modified embodiment of the invention.

FIG. 9 is a partial plan view of the nose portion of the modified flex wing shown in FIG. 8.

FIG. 10 is a side elevation of the structure shown in FIG. 9, some parts appearing in section on the plane iii-4&0 in FIG. 9 looking in the direction of the arrows.

PEG. 11 is a view in section on the plane 11-11 in FIG. 10 looking in the direction of the arrows.

FIG. 12 shows in detail the mounting of the propeller at the trailing end of the craft taken partly in section on the projected plane 1ii10 of FIG. 9.

In FIGS. 1, 2 and 6 the entire toy paraglider is shown to constitute a flex wing type of aircraft having the characteristic main spar 12 extending rearward from the air entering nose portion of the craft, indicated in general as 13, and two lateral spars 14 and 15 angled relatively to the main spar at respectively opposite sides thereof. Each of lateral pars 14 and 15 is joined to the main spar 12 by means of a terminal fitting 16 at the nose of the craft which snugly sleeves over and is rigid with the front end portion of the hollow tube 17 that forms the major length of the main spar. Fitting 16 has two branching spur sockets 18 into whose open ends the lateral spars 14 and 15 are inserted respectively. The socket 18 are angled so that the lateral spars are inclined upward in relation to the main spar as they sweep to the rear from the nose of the craft.

The triangular spaces 19 and 20 between lateral spars 14, 15 and the main spar 12 at respectively opposite sides of the latter are each bridged by a flexible wing heet 21 which connects the main spar to the lateral spars and produces the lifting force for the craft when the latter is impelled nose foremost through the air, as by a propeller 26. Said width of the wing sheet is greater than the width of the triangular spaces spanned thereby so that in flight the sheet archs up to a higher level than the spars as evident from FIGS. 5 and 6.

The angulation of the lateral spars relatively to the main spar, and therefore the width of the triangular spaces between the spars, is maintained by a spreader wire 22 of the shape and disposition shown most clearly in FIG. 5. Wire 22 may be somewhat resilient so that its U-shaped center well 23 clamps the wing sheet 21 against the main spar 12 and its cup-shaped end portions 24 clamp the side margins of the wing sheet against the lateral spars.

Propeller 26 is rotated by a prime mover contained within the hollow of the main spar in the form of a twisted loop of elastic band 27 and is bladed to drive the craft nose foremost. For purpose of illustration it will be assumed that propeller 26 rotates in such direction that its blades attack the air in a clockwise direction of propeller rotation in FIG. 1 (counterclockwise in FIG. 6). This exerts a torque tending to roll the craft in the opposite direction, namely counterclockwise in FIG. 1 or clockwise in FIG. 6. By the present improvements this tendency of the craft to roll in flight about the longitudinal axis of main spar 12 is counteracted, and the craft accordingly stabilized, by a differential of lifting force produced in flight by the wing sheet on opposite sides of the main spar 12. Such differential is brought about by disposing the lateral spar 14 at a greater angle to the main spar than is the lateral spar 15. This exposes to the air a greater expanse of sheet area over the triangular space 19, than over the triangular space 20 and hence makes the lifting power of the wing sheet in space 14 greater than in space 20.

The present improvements further enable the hollow main spar 12 to house the prime mover or motivating elastic band 27 in a way to be easily removable therefrom and in a way to be energized to selective extents by twisting it from the outside of the main spar while so housed. For this purpose propeller 26 is fixed on the outboard end of a power transmission spindle 28 for which rotary bearing is provided by a cap 29 having a spider shank 30 whose vanes fit tightly but removably into the open end of the cylindrical wall of the main spar 12 at the rear end thereof. The inboard end of spindle 28 is hooked into the rear end of the looped elastic band 27 so that automatic untwisting of the band rotates the spindle and thereby serves as a power source for rotating the propeller 26 to propel the craft nose forward.

The opposite or front end of the looped elastic band at the nose of the craft is engaged by a hook on the inner end of a turn button 36 whose body is equipped with rearward projecting lugs that enter corresponding open notches 38 in the front end of the terminal fitting 16 of the main spar. This enables the turn button to be maintained in selective rotary positions relative to the main spar when the lugs are biased into occupancy of the notches by the longitudinal pull of the elastic band. The stretch of the band enables the lugs to be Withdrawn from the notches by pulling forward on the turn button so that as much or as little twist can be imparted to the elastic band as desired for storing up motive power therein.

FIGS. 2, 3 and 6 best show a foreleg 43 fixedly anchored by a stud 47 and a wrapped band 48 against the bottom surface of the terminal fitting 16 and depending therefrom at a rearward slant for contacting the ground to serve as landing gear when the craft glides to earth. Foreleg 43 may comprise a somewhat resilient stiff wire having a hooked lower end as shown in FIG. 2.

In keeping with improved practice in the construction of a toy paraglider such as disclosed in the aforesaid copending patent application the present craft is preferably but not necessarily equipped with a winged stabilizer 44 whose standard supports the wings in an elevated position above and a little in front of the nose of the craft and the base 49 of the standard 45 is non rigidly clamped against the top surface of the terminal fitting 16 of the main spar by means of a removable rubber band 46.

So long as the general proportions of structure are approximately as shown in the drawings the dimensions of a craft embodying these improvements may vary considerably. Depending somewhat on overall size it is recommended that the angle between lateral spar 14 and the main spar 12 be about 28 degrees whereas the angle between lateral spar 15 and the main spar is preferably less and suitably can be 24 degrees. These proportions may be interchanged depending on the direction of rotation of the propeller. All of the three spars may be made of plastic tubular material or of comparably light weight materials, such as cardboard having sutficient strength.

In the embodiment of the invention shown in FIGS. 8 to 12 inclusive, the main spar 52 comprises a simple straight strip of solid, light weight, balsa wood preferably of rectangular cross-sectional shape requiring no special shaping for attaching thereto certain fittings which constitute other parts of the craft. Such fittings are so made and shaped that they embrace and cling tightly to the main spar 52.

The fittings herein shown comprise an integral nosepiece 53 of molded plastic and a tailpiece 54 which likewise may be molded of plastic material. The rear end of nosepiece 53 is hollow and forms an open socket 55 receptive to and tightly hugging the front end of main spar 52. The forward portion of the tailpiece 54 is likewise hollow and forms a socket 56 receptive to and tightly hugging the rear end of the same spar 52.

Nosepiece 53 includes an upstanding fin 57 which serves as a standard that is topped by a narrow arched support shelf 62 adapted to carry a removable stabilizing airfoil 58 that is made of normally fiat sheet material preferably resilient to oppose flexure but permitting the airfoil to be bowed upward temporarily for installing it in position on the support shelf 62. For this purpose there are two keyhole-shaped apertures 59 in the airfoil which can be slipped over the large retaining heads of studs 60 on shelf 62 in a manner to become lodged retainingly under said stud heads when the self-straightening tendency of the airfoil to return to its originally fiat shape from its temporary bowed-for-installing condition spreads the distance separating the apertures of grommet holes 59.

Nosepiece 53 further includes a hook formation 61 for anchoring one end of a single or plural loop of elastic band 65 by means of which the propeller 66 of the craft is motorized. Nosepiece 53 further is provided with a narrow slanted notch opening downward from a thickened base portion of the fin 57 just ahead of the socket 55 and adapted to have squeezed into it and to hold firmly the strip metal yoke 67 for supporting the lateral spars 68 and 69. Each of the two free end portions of the yoke 67 are angularly bent in relation to the mounted span 70 of the yoke as is seen in FIGS. 8, 9 and 11, and each of these end portions is bent into a clip formation 71 which is adapted to receive with a tight clinging fit the forward end portions of the lateral spars 68 and 69 respectively. Said end portions of the yoke are further angled to slant upward in relation to the level of the main spar 52 as is shown in FIGS. 10 and 11. This imparts to the lateral spars 68 and 69 a corresponding upward slant as they sweep backward from the nose of the craft for the purpose explained with respect to the lateral spars 14 and 15 of the form of the invention shown in FIGS. 1-8 inclusive. Bumps 74 orient yoke 67 sidewise of the nosepiece 53.

The angular spread of lateral spars 68 and 69 is further determined and maintained by a spreader strip 72 functioning as does the spreader wire 22 in FIGS. 1 to 8, inclusive, and which likewise dips into a mounting well formation 73 having enough resilience to serve as a spring clip that will hug the sides of the main spar 52 with a clinging fit. Also as in FIGS. 1 to 8, a wing sheet 78 which may be of very thin flexible paper of the type used in kites underlies the main spar 52 and intervenes between the mounting well 73 and the main spar. To guard against sheet 78 being torn where squeezed against the spar by spreader strip 72 it is good practice to insert between the wing sheet and the well formation 73 of the spreader strip a swatch 79 of thin flexible sheet material that is tougher than the material of the wing sheet.

The angularly related edges of the wing sheet are hemmed over, and prior to the mounting of the lateral spars in the yoke 67 the former are inserted respectively in these hems of the wing sheet. The forward or nearest together ends of the lateral spars can then be inserted in the yoke 67 as aforesaid with the wing sheet spreading under and extending past the main spar 52. After saddling spreader strip 72 upward to clamp the wing sheet 78 and protective swatch 79 about and against the side surfaces of the main spar 52, the hem encompassed lateral spars 68 and 69 are pressed into the embrace of inwardly hooked ends 80 of spreader strip 72. This more positively maintains the designed angulation of the lateral spars established by their mounting yoke 67 and prevents slipping of the lateral spars lengthwise within the hems of the wing sheet. Staying attachment of the wing sheet to main spar 12 is made further by slipping a U-shaped spring clip 81 upward over the main spar near the tail end thereof with the wing sheet clamped between the clip and the spar as shown in FIG. 12.

FIG. 12 shows details of the tailpiece 54 whose molded shape includes an upstanding post 84 that affords rotary and thrust bearing for the drive spindle 85 of propeller 66. The propeller is carried by and free for a limited extent of rotation on spindle 85 and is driven to rotate therewith in either direction by means of the hooked over outboard end 86 of the spindle 85 which also pulls the propeller hub forward into thrust abutment against bearing post 84 when the looped rubber band 65 is stretched to drivingly engage in the open hook 87 formed by the inboard end of spindle 85. A friction reducing, thin metallic thrust washer 88 is inserted between the propeller hub and the bearing post 84.

The main spar 52 is saddled about midway of its length by a slidable weight clip 82 which is clear of the wing sheet 78 so that it can easily be adjusted fore and aft on the spar. It fits the spar with sufiicient resilient cling to maintain its adjusted position until readjusted. If, after taking off, the craft tends to nose up too much or stall the weight 82 should be shifted forward. If the craft tends to nose-drive or glide downward too suddenly, the weight should be shifted toward the rear. Launching should be against a steady wind or breeze of less than miles per hour. The rubber band motor can be wound as much as three hundred turns by fingering the propeller. If the spread of the wing sheet is greater at the left side of the main spar than at the right side (as explained in connection with FIG. 1) the propeller will be turned in a counterclockwise direction to Wind in FIG. 1, or clockwise in FIG. 8, so that the rubber band will drive the propeller in opposite direction when taking off. This gives the craft a tendency to roll in a direction that will be counteracted by the broader spread of the asymmetrical wing sheet as before explained.

A practical size for a toy flex wing of the construction shown is for the wing sheet 21 or 78 to measure about 19 inches along the main spar and to have a spread at the trailing end of the craft of about inches.

Simple directions will enable a child or adult who is experienced with kiting or model aircraft to put together and operate the parts of the toy hereinbefore described. This is particularly true of the balsa wood spars of FIGS. 8-12 because parts made of this material have long been employed in the construction of home assembled toy airplanes. It use in flex-wings is believed to be new. When knocked down, the spars, the nosepiece, the tailpiece-propeller subassembly, mounting yoke 67, spreader strip 72, stabilizer 58, elastic band motor and the wing sheet can all be arranged in side-by-side parallel relation within a narrow compass. Thus arranged they can all be contained in an elongate, very narrow box or bag of transparent material to form a compact and attractive sales package. The manner of assemblage without the use of tools will be evident from the foregoing description of the construction.

Many departures from the shapes and arrangements of the parts herein shown may be made within the principles of the invention and such variants are functional equivalents are intended to be covered by the appended claims.

We claim:

1. A toy aircraft of the flex wing type comprising a main spar extending rearward from the air entering nose of the craft, lateral spars angled relatively to said main spar at respectively opposite sides thereof joining said main spar at said nose of the craft, a flexible wing sheet bridging triangular spaces between said main spar and each of said lateral spars, means to maintain said lateral spars so angled with respect to said main spar that on of said spaces is substantially wider than the other of said spaces, and a bladed propeller at one end of said main spar powered to cause its blades to attack the air in such rotary direction that the resulting tendency of the craft to roll is opposed in flight by the relatively stronger lifting tendence of said wing sheet over the wider of said triangular spaces.

2. A toy aircraft of the flex wing type comprising, a hollow tubular main spar extending rearward from the air entering nose of the craft, lateral spars angled relatively thereto at respectively opposite sides thereof joined to said main spar at said nose of the craft, a flexible wing sheet bridging triangular spaces between said main spar and each of said lateral spars, a propeller mounted at one end of said main spar to rotate about the longitudinal axis thereof, and a source of power operative to rotate said impeller contained within the hollow of said tubular main spar.

3. A toy aircraft as defined in claim 2, together with a foreleg attached to the said main spar near the said nose of the said craft and depending therefrom for contacting the ground to serve as landing gear.

4. A toy aircraft as defined in claim 2, in which the said source of power is a stretchable twisted elastic band extending lengthwise of the said main spar.

5. A toy aircraft as defined in claim 4, in which the said propeller is located at the rear end of the said main spar, and one end of the said elastic band is drivingly and removably connected thereto, together with means at the nose end of said main spar to anchor the opposite end of said elastic band in a manner enabling said band to be twisted to selective extents from the outside of the main spar.

6. A toy aircraft as defined in claim 5, in which the said means to anchor the said elastic band includes a turn button attached thereto and cooperatively engaged with the nose end of the said main spar in a manner to be set and adjustably maintained in different rotative positions about the axis thereof, whereby to vary the extent of twist in said band.

7. A toy aircraft as defined in claim 6, in which the said elastic band is connected to the said turn button in a longitudinally stretched condition, thereby to draw said turn button toward its said engagement with the end of the said main spar.

8. A toy aircraft as defined in claim 6, together with a rotary bearing cap removably engaged with the rear end of the said main spar in a manner precluding turning of the former about the axis of the latter, and a power transmitting spindle carrying the said propeller at the outboard side of the said bearing cap drivably attached to the said elastic band at the inboard side thereof.

9. A toy aircraft of the flex wing type comprising, a main spar extending rearward for the air entering nose of the craft, a nosepiece equipped with a stabilizing wing and separably joined to the leading end of said main spar, spur sockets branching fixedly from said nosepiece in directions rearward outward and upwardly inclined therefrom, a tailpiece separably joined in fixed relation to the trailing end of said main spar, a propeller having a driven spindle journaled in said tailpiece, lateral spars separably mounted in said spur sockets respectively, a wing sheet extending past said main spar from one to the other of said lateral spars, and a twistable elastic stretched between said nosepiece and said propeller spindle for storing and paying out power to rotate said propeller.

it). A toy aircraft as defined in claim 9, in which the said wing sheet extends under the said main spar and the said elastic extends along said main spar thereabove.

lll. A toy aircraft as defined in claim 9, in which the said propeller spindle has an end at the inboard side of the said tailpiece forming an open hook-shaped loop to which the said elastic is removably anchored in a manner yieldably to draw the said propeller forward into thrust engagement with said tailpiece.

12. A toy aircraft as defined in claim 9, in which the said nosepiece includes an upstanding fin topped by a support shelf having button headed studs on its upper surface, and the said stabilizing wing comprises an airfoil of thin sheet material having grommet holes and sufficiently flexible to be bowed for installing said grommet holes in holding engagement with said studs.

13. A toy aircraft as defined in claim 9, in which the said nosepiece has a thin-walled hollow portion forming a pocket receptive to one end of the said main spar with a tight fit, and the said tailpiece has a thin-walled hollow portion forming a pocket receptive to the other end of the said main spar with a tight fit.

14. A toy aircraft as defined in claim 13, in which he said main spar comprises a straight solid bar of light weight balsa wood, and the said nosepiece and tailpiece comprise integral bodies of molded plastic material.

15. A toy aircraft as defined in claim 9, in which the said spur sockets comprise bent ends of a yoke of strip metal separably attached to the said nosepiece.

16. A toy aircraft as defined in claim 15, in which the of shape and size resiliently to embrace the said lateral said nosepiece contains a downward opening notch, and spars respectively. the said yoke is firmly and removably lodged in said notch References Cited by the Examiner 17. A toy aircraft as defined in claim 16, together 5 UNITED STATES PATENTS with a spar spreader comprising a continuous strip of 2,537 560 1/1951 Wanner 244 153 resilient metal crossing the said main spar and having at 21814907 12/1957 Sears U-shaped well formation of size and shape to clamp removably thereon, said spreader strip having bent ends RICHARD C. PINKHAM, Primary Examiner. 

1. A TOY AIRCRAFT OF THE FLEX WING TYPE COMPRISING A MAIN SPAR EXTENDING REARWARD FROM THE AIR ENTERING NOSE OF THE CRAFT, LATERAL SPARS ANGLED RELATIVELY TO SAID MAIN SPAR AT RESPECTIVELY OPPOSITE SIDES THEREOF JOINING SAID MAIN SPAR AT SAID NOSE OF THE CRAFT, A FLEXIBLE WING SHEET BRIDGING TRIANGULAR SPACES BETWEEN SAID MAIN SPAR AND EACH OF SAID LATERAL SPARS, MEANS TO MAINTAIN SAID LATERAL SPARS SO ANGLED WITH RESPECT TO SAID MAIN SPAR THAT ON OF SAID SPACES IS SUBSTANTIALLY WIDER THAN THE OTHER 